George lloyd wigg



UNITED STATES PATENT, OFFICE.

GEORGE LLOYD WIGG, MATTHEW STEELE, AND XVALTER JOHN WVIGG, OF

' RUNCORN, COUNTY OF CHESTER, ENGLAND.

OBTAINING FERRIC OXIDE FROM THE WASTE LIQUORS OF COPPER-WORKS.

SPECIFICATION forming part of Letters Patent No. 370,511, dated September 2'7, 1887.

Application filed May 15, 1886. Serial No. 202.312. No specimens.) Patented in England October 17,1884, No. 13,722; in France July 22, 1885, No. 170,251, and in Belgium July 23, 1885, No. (39,684.

To aZZ whom it may conc ern:

Be it known that we, GEORGE LLOYD Wise, MATTHEW STEELE, and WALTER J OHN Wise, subjects of the Queen of Great Britain, resid- 5 ing at Runcorn, in the county of Chester,

England, have invented a certain new and useful Improvement in Treating Certain Residual Liquors to obtain Oxide of Iron and Sulphate of Lime or Plaster-of-]?aris, (for which we have obtained Letters Patent of Great Britain, N 0. 13,7 22, October 17, 1884; France, No. 170,251, July 22, 1885, and Belgium, No. 69,684, July 23, 1885, and nowhere else;) and we hereby declare that the following is a full, clear, and

i eXact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

The object of the invention is to treat the residual liquor obtained in the precipitation of copper by the wet process and the residual chlorideof-ealcium liquor obtained in the man ufacture of chlorine by theVVeldon process in such a manner as to obtain sulphate of limeas plaster-of-paris or pearlhardening-practi- 2 5 cally pure and in fit condition for use by papermakers, and also oxide of iron ready for use as a pigment; and in order that our said inven tion maybe fully understood we shall now proceed to describe the system, mode, or mannor in or under which the same may be carried into practical effect.

The composition of the waste copper-liquors it is proposed to treat may be generally stated as containing about sixteen (16) per cent. of

3 5 sulphate of soda, ten (10) per cent. of chloride of iron, three (3) per cent. of chloride of sodium, traces of other salts, and seventy-three (73) per cent. of water, though said propon tions will necessarily vary, and. must not be 40 taken as matters of limitation.

In the first place, after determining from the strengths of the liquors their fixed proportions, the residual copper-liquors (which may be neutralized or not, as circumstances demand) 5 and the residual chloride-of-calcium liquors are brought together in large vessels and thoroughly agitated by manual or mechanical power until the whole mass becomes homogeneous. During the time and immediately succeeding the time occupied in this operation the free sulphates contained in the residual copper-liquors combine with the calcium contained in the residual chloride-of-caleium liquors, forming a white bulky precipitate, which we now allow to settle. When the sep aration is complete, we arrange the clearliquor and the white precipitate thus obtained in different receptacles, proceeding with the two distinct branches of our invention at one and the same time, in the following manner:

To obtain pearl-hardening, plaster-of-paris, or sulphate of lime, the white precipitate is first treated with dilute hydrochloric acid for the purpose of clearing it of any iron. It is then passed through filter-presses, or other mechan ical appliances, for the purpose of washing out all impurities and pressing to such a consistency as the requirements of the trade demand. Treating; this same precipitate with gentle heat, we obtain a parian-plaster, or plaster-of-paris, of the first quality.

To obtain oxide of iron, we treat the clear liquor already referred to, or from residual copper-liquors direct, with an equivalent of milk of lime for the purpose of precipitating the iron as an oxide. The dark-green precipitate which readily forms is then further oxidized by injection of air, chlorine, or other oxidizing agent, washed through filter-presses or other mechanical appliances, and furnaced So to obtain the various shades of color.

WVe claim- 1. The method herein described of obtaining oxide of iron from the residual liquors obtained in the precipitation of copper by the wet process and the residual chloride-of-calcium liquor obtained in the manufacture of chlorine by the Weldon process, which consists in first mixing and agitating the said. liquors; secondly, separating the precipitate and su- 9o pernatant liquor; third, treating the liquor with an equivalent of lime, and, finally, oxidizing and furnacing the precipitate last obtained, substantially as and for the purposes specified. p 5

2. The method herein described of obtain ing sulphate of lime, or plaster-of-paris, from the precipitate to remove impurities and prethe residual liquors obtained in the precipitapare it for the market, substantially as and for tion of copper by the wet process and the rethe purposes specified. V sidual chloride-of-caleium liquor obtained in the manufacture of chlorine by the Weldon process, (as a by-produet in treating said WALTER JOHN G liquors to obtain oxide of iron,) which consists in first mixing and agitating the said liquors; secondly, separating the precipitate and supernatant liquor; third, treating said precipitate with dilute hydrochloric acid, and, finally, washing, pressing, and gently heating Witnesses:

G. R. H. HARRISON,

Clerk, Runcorn. THOMAS HARRIS,

Cashier, Runcorn. 

